[6]The respondent submitted that this Court should draw a distinction between invalidity raised as a defence under section 59 of the Patent Act and invalidity raised as a counterclaim under section 60 of the Patent Act. The respondent’s argument is that invalidity raised under section 60 has a larger impact in that it results in a declaration in rem available to anyone.

[7]From the point of view of costs, that distinction does not reflect the reality of a patent trial. Once invalidity is raised, whether as a defence or by way of counterclaim, the trial judge is bound to deal with it. The issues are the same in either case, the only difference being the consequences for the plaintiff. Those consequences do not justify denying a successful defendant its costs.